Armature-actuating mechanism



June 19, 1928. 1,674,094

P. BROWN ARMATURE ACTUATING MECHANISM Filed Ma1 ch24, 192's 2 Sheets-Sheet l INVENTOR.

A TTORNEYS.

Patented June 19, 1928.

UNITED STATES PHELPS BROWN, OF SPRINGFIELD, MASSACHUSETTS.

ARMATURE-ACTUATING MECHANISM.

Application filed March 24., 1926. Serial No. 97,011.

This invention relates to improved mechanism for actuating the armature of a magneto. v

The invention is an improvement on that of U. S. Patent No. 1,517,948, granted December 2, 1924, on an invention of Phelps Brown and Ira E. Hendrickson. Like that invention the present one contemplates driving mechanism of a type wherein the armature may be initially moved out of contact with its magnetic poles by an inelastic transmission of force from the drive shaft, immediately followed up by a transmission of force from previously stressed elastic means; or wherein the armature may be driven entirely by the described inelastic transmission of force. operation is useful on starting or low engine speeds and the latter for higher engine speeds. In shifting from the first to the second plan of operation, the desired advance in speed is automatically obtained.

The object of this invention is to provide an improved armature actuating mechanism for the general purpose, above set forth, and to provide such a mechanism which more convenient to operate, cheaper to manufacture and assemble, and simpler and more compact in form.

Other objects and advantages will appear in the following description and will be pointed out in the-appended claims.

The invention will be reference to the accompanying drawings, in which:,

Fig. 1 is a front elevational view of a magneto embodying the armature actuating mechanism of this invention;

Fig. 2 is a. bottom plan view taken on the line 22 of Fig. 1:

Fig. 3 is an enlarged but fragmentary view, taken similarly to Fig. 2, but showing the armature actuating mechanism shifted into positionfor direct drive;

Fig. i is an enlarged cross sectional view taken on the line 4 l of Fig. 1;

Figs. 5 and 6 are enlarged but fragmentary cross sectional views taken on the lines 55 and 66. respectively of Fig. 1;

Fig. 7 is a fragmentary rear elevational view illustrative of the devices for shifting the armature actuating mechanism;

Fig. 8 is a sectional plan view taken on the l ne 88 of Fig. 7;

Fig. 9 is a sectional elevatioual view taken on the line 99 of Fig. 4;

The first plan of.

disclosed with Fig. 10 is an enlarged sectional view illustrative of the mounting of the lever arms of the armature actuating mechanism; and

Figs. 11 and 12 are plan and elevational views, respectively, of one of such lever arms.

The present invention, being directed primarily to mechanism for actuating the armature. is largely independent of the particular details of construction of the other parts of the magneto. The magneto shown is illustrative of a general type and is one example of many various magnetos of this general type with which the invention may be used.

The magneto illustrated is, with the exception of the armature actuating mechanism and the armature mounting, constructed in the manner fully disclosed in United States Letters Patent No. 1,557 ,976, granted October 20, 1925, on an invention of Phelps Brown and Terrence G. Louis and reference is made to this patent for a more complete disclosure of the general construction of the magneto.

Theframe A of the magneto is essentially like that of said patent except that it is extended to one side to provide for the mount ing of the armature actuating mechanism and except that .it is provided with supporting legs 10, which support it from a lower housing exemplified in part by the bed 11. The magnets 12, cores 13, primary coils 14 and secondary coils 15 are supported from frame A in the same manner shown in said patent,the lower ends of the cores being clamped between the frame proper and a separate frame member l6-by bolts 17. The interrupter casing 19 is fixed in frame member 16 (Fig.6) and carries a fixed breaker point 20 insulated from the casing. The latter also slidably receives a plunger 21 which carries the movable breaker point 22 and has a stem 23 extending loosely through a lug 2-1 fixed to the armature 25. A spring 26 acts between lug 24 and the base of plunger 21 to lift the latter, whenever possible. and hold the breaker points 20 and 22 in engagement. These points are separated when an abutment 27 on stem 23 is engaged and moved by the under side of hi 2 L. A second abutment 28 is provided below abutment 27 to permit operation of the breaker points by other mechanism, as will hereinafter appear. The electrical and magnetic circuits are, or may be, like those shown in the patent above referred to.

The armature 25 is pivotally mounted to tionrto another to effect the twokinds of V mature;

swing toward and into contact with the lower ends ofcores 13 and away from thesame, thereby efi'ecting a variation of flux 1n the magnetic circuit in a known manner. This pivotal mounting is effected by fixing the armature toa shaft 30 (Fig; 2) which is rotatably mounted in two spaced lugs 31 formed as integral parts of frame A and disposed near the back edge thereof. A pair of armature return springs 32 (Fig; 1) act between the bed 11 and armature 2 with a tendency to lift the latter toward and into contact with-cores 13. 'The armature is fixed to shaft 30' by. cap screws 83 (Figs{ 2 and 6)' which each pass freely throughelug 24, the laminations of armature 25, a sleev'eg34 and one ear of a split collar lateral extension of frame-A by means which arm the shaft may be turned to oper atethei armature; Arm 36' has a. surface 37 and-carries a stud 38,-these parts 37 and 38 forming abutments movable with thear- Qn'e or' the other of these abutments is engaged by the armatureac-tuating mechanism according to whether the armature is to'be driven' in=its fiight away from thepoles entirely j by an inelastic transmission;- of force or by the expansive effort of" a previousl'ytstrcssed' elastic means followingthe breaking of the' magnetic hold on the armature force-5., V i

The armature actuating mechanism includes a' unit which is mounted'on shaft 30' adj acentarm '36" for swingingmovement and" I v V Karma-cure 25 from shaft 56 results.

which'sis also mounted to freely slide in an axial directfionon' this shaft from one. posiarmature movement just described. This unit: comprises two levers40 and 41 which are-,ormay be; exact counterp'arts; One of these levers is showrr in detail: in Figs. 11

and 12' and, as will bese'enfrom these figsideflbyiside-in contiguous relation. VVhen thus arranged; they are mounted? on a common-.hub-42 (Fig; lO) which in turn is slidably mounted' on-shaft 30. The levers are held against relative-axial displacement on V the hub between :a': flange- 43 and the crimpc'd' I over end 44 of hub 42; The flange 43, in

cooperation withi a: similar. flange 45; on. hub

by an inelastic transmission of 42, affords a clutch. collar having; aperipheral groove 46. The lever'4O has an outwardly turned lug 47 which underlies lever 41 and; the latter hasasimilar lug 48 which overlies the lever 40 (Figs. 4 and 5). These lugs 47 and 48 limit the extent to which the levers can move away from one another. The free ends of the levers 40 and 41 are bent in reverse directions (Fig. 3) and have projections 49 and 50 (Figs. 4 and 5), respectively, which by reason of the bending of the levers,are so positioned that part of one'p'rojection will overlie part of the other projection. Consequentlypthese projections serve as abutments which will engage and limit the extent to which the levers maybe moved toward one another. An armature drive spring '51, in the shape of a coil spring,

is interposed between the free ends of the levers 40 and 41, the projections 49 andtO being of a size to enter ithin the coils of the spring and hold the samein place. The lever 40 has an integral lug 52 which is turned outwardly and adapted:v when the unit is moved to one position (F igs; 8 and 9), to overlie the abutment 37 on armature driving lever 36,formmg the abutment hereinbefore referred'to. When the unit 1s- 'movcd to its other position (Fig; 2), the" abutment 52 is carried out of overlying rc-' lat-ion w1th=lever-36', whereby lever .40-can be de iressed i without directl movin lever V y a:

36. Lever 41.. has an integral abutmentforming projection 53, similar to member 52, which project-ion 58 {always overlies the stud 38,. irrespective ofwhich position the unit occupies.

by an eccentric 55 formed'on' a driving shaft 56 rotatably mounted inframeA; The eccentric 55 is encompassed 'byan anti-friction The lever 40 is intermittently depressed roll57 which-overlies and engages the abutment 52 on lever 40. hen this abutment 52 also overlies the surface 87 of lever36, as

indicated 'inFig; 4,ja' direct. dr-ive of the The drive spring 51 is not compressed, or atfleast' not compressed to any substantial degree and lever 36 is moved by the eccentric 55in just the sam manner as if this level-were dlre'ctly engaged bythe' eccentric. WVhen,

however, the driving unit is shifted, by

means to be described, so that abutment'52 is moved out of overlying relation with the surface 37 of lever, 36, a quite difierent action The eccentric depresses lever takes place. 40 and the latter moves toward lever 41, thereby compressing? the drive spring 511 Thelatter, when fully stressed, is not, how ever, sufficient to overcom the force of'mag netic attraction which holds the armature lever 41, stud 38. lever 36, and shaft 30 to armature 25, after the drive spring 51 has been stressed. This inelastic transmission of force serves to break the magnetic hold on armature 25 and move it a very short initial distance away from its poles. As soon as the magnetic hold is broken, the previously stressed drive spring51 comes into play and moves the armature away from its poles at a speed independent of engine speed.

The driving unit may be shifted axially on shaft '30 from one to the other of its driving positions by any suitable means. As shown, a plate 58 is slidably mounted on the rear face of frame A (Figs. 7 and 8). A screw 59 and a pin 60, fixed to frame A, pass through slots in plate 58 and guidethe same in its sliding movement. A lever 61, mounted to freely turn on screw 59 as a pivot, has cam surfaces 62 at its lower end which engage projections 63 on plate 58, whereby on swinging lever 61, plate 58 may be shifted. Plate 58 has a depending arm 64 which rides in groove 4.6 of the clutch collar, above described.

In the magneto described, the breaker points 20 and 22 separate, for the purpose of opening a normallylshort circuitcd primary winding, at an intermediate point in the flight of the armature away from itspoles. These breaker pointswill, therefore, close at a corresponding point in the return movement of the armature. Thus, the primary winding will'be short circuited during the latter part of the return travel of the arma ture. This is desired to assist in securing a relatively quiet seating of the armature on its poles. The short circuited primary winding prevents a rapid building up of flux in the magnetic circuit, which would otherwise occur as thearmature approaches its poles and which would tend to draw the armature into contact with its poles with a sharp noise. After the armature has been seated on its .poles, all of the beneficial effect of the short circuitcd primary winding has been obtained and to continue this condition would be detrimental in that the desired building up of tluxto a maximum intensity in the magnetic circuit would be unnecessarily delayed. Therefore, means are provided to open the primary winding after the armature has been seated on its poles and to subsequently close this circuit before the. armature again leaves its poles.

lVhile the above object has been heretofore accomplished, as in the Brown and Clark U. S. Patent No. 1.489382. dated April 8, 192 i. I accomplish it in this magneto by'a specifically different and improved mechanism which will now be described. Referring to Figs. 2 and 6, the second and lowest abutment 28 on the stem 23 of movable breaker point 22 lies directly beneath the forked end of a short lever 65, which is fixed to one end of a short shaft 66 rotatably mounted in a lug 67 depending from frame member 16. Fixed to the other end of shaft 66 is a lever 68, the free end of which is urged upwardly against a cam 69 by a spring 70, fixed to one of the bearing lugs 31. Cam 69 has two diametrically opposed projections 71 (Fig. 6) and is fixed to one end of a short shaft 72, rotatably mounted in a hub 7 3, depending from frame A. 'The other end of shaft 72 carries a gear 74 9) which is driven by a pinion 7 5 fixed to an extension 7 6 of the drive shaft 56. v The shaft 72 is driven at one half the speed of shaft 56. Hence, as the armature is moved through one complete cycle on each revolution of shaft 56, it is necessary to provide the two projections 71 on cam 69. In Fig. 6, the parts are shown in the relative posi tions which prevail just after the armature has engaged its poles. Vith shaft 72 turning in a clockwise direction, it is apparent that one of the projections 71will shortly depress lever 68 and thus shaft 66 and lever 65, whereby the breaker points 20 and 22 will be separated. Continued movement of shaft 72 will cause this projection 71 to ride off the end of lever 68, thereby allowing the breaker points to be ree-ngaged by spring 26. The reengagement of the breaker points occurs just shortly before the armature 25 starts to leave its poles 13.

The operation of the magneto will sufli ciently appear from the foregoing description and itis essentially like that of the magneto disclosed in Brown & Hendrickson Patent No.1.517,948, dated December 2, 1924, except for the extra opening and closing of thebreaker points, which has just been described.

The action of the armature driving mechanism, whereby the armature may be driven away from its poles either entirely by an in--.

elastic transmission of force from the drive shaft or by an initial inelastic transmission of force followed by an elastic transmission offorce from a previously stressed drive spring, is also broadly similar to that of the last named patent. However, the change from one form of drive tothe other is effected by different means and in an approved manner. It is no longer effected by inserting a spacer (as between projections 49 and 50) to prevent thestressing of the drive spring and cause the armature to leave its poles at an earlier time than when stressing of the drive spring is permitted. Necessarily. such a spacer must be moving cont-inually and is not convenient to operate. In the present case. the entire driving unit shifted axially on its support by means of the lever 61- and clutch groove 46, to? effectthe? change in a most convenient manner.

Also; such driving unit is of a simplifiedand improved character, especiallyfromthe manufacturing. point of VIEW. It consists simply of two punchings, pivoted together SClSSOlSyfHShlOIl on a; common hub having; a clutch-collar, and a drivespringc The two punchings are, or may. be, exactcounterparts and can be produced? in quart tities at low cost. [ThlSyClI'lVlIlQ' unit notonly presents important advantages froin the manufacturers joint of. v-iew, biit it' als'o;

'has important advantages from the users 15- point'of view. It is not onlymore convenient t'o' operatc'but it isstiii dy-and reliable in operation and compact inform.

The invention has been; disclosed herein,

in an embodiment at presentp 'eferred, for illustrative purposes but t he scope as the invention is defined the appended claims rather than by the. foregoingdeseription What I! claim is 1; All armature. driving mechanism for magneto, comprisingiin combination with a partconnected to the armature for moving the same, an operating member capable of beingv bodilyc shifted into or out ofpositiontoengage said part, means foi'"applyiiig a driving force to said operating niembeii, whereby thelatter will be moved! and-(11 v positioned to engage said part will: move? the.

armature," a secondAoperat-ing. member also adapted to engage said part and elastic means: through which the fiiifttnamed op erating'member when shifted-out of position nijay tr-ansinita. driving force to the other operating" member; and thus to said:

part, whereby the armature may be driven y r r ing' force: when desired.

2., Armature driving mechanisnn for av magneto, comprising, two relatively movable parts, resilient means EL SOCIEIlZQCl therew1th.

and stressed by their, relative movement in one direction, means for applyinga driVing,

force'to one ofsaid'parts to thereby stress said resilient means, and .thenmove said.

other part,- the latter transmitting the dr-iv-' ingv force to said armature, and .means for bodily shifti'ng said. parts with their, associated resilieiitmeans so that thefinstnamed part becomes effective to transmit. an inelastic driving force to the armature;

j 31 Armature driving. mechanism for a i'mag neto, comprising, in combination with the armature and a part connected to move the same, two pivoted leverstoone of which the driving force is applied and the otherof which is'adapted to engage said partand transmit the force from the: first named lever to the armature, resilient means associated with said levers and stressed by said' transmission of-force, and means for shifting one of said levers so thatj the first named lever ii elastic transmission. fromsaid drivj 7 may directly, engage said. part and effect. an

inelastic transmission ofiforce to the armature.

4..Ar-mature driving mechanism for a magneto, comprising, an assembly consisting: of tWo relatively movable levers with resilient means interposed between them,'

means-for applying a driving force toone of said levers which force stresses said resilient means and then moves the second lever, the-latter adapted to transmit the force to t'helarmatur'e, andrmeans for bodily shittingsaid assembly to cause the first ,nained lever to transmit thediiving. force to the armature and render. the firstv named transmission ineffective to drive the armature. i

Armature driving mechanism. for a magneto, comprising, two pivotedlevers, ca-

pable 01": relative swinging movement,- resilient means associated with the levers and stressed their relative movement in one direction, means for applying:v a. driving,

force to one of said levers which force stressessaid resilient means and then moves the second leveiythe latter adapted totran'smitthe force to the armature, and means for shifting, one of said levers: in a direction parallel to its pivotal axis to cause the first named lever to transmit the driving force to :the. armature and render the first named transmission ineffective'to drive the armature; 1 V t 6. Armature driving niechanisnifor a magneto, comprising, two pivoted levers, elastic means tending to swingthemapart,

means for limiting.- the extent of suchJrelastress said elasticineans, a part in the path of the other lever by means of which the armature may be moved,- a second part by tive' swinging movement, means for applying forceito oneof said-levers in a directionsuch as toswing them toward each other and; stress said elastic. means,a part in't'he path of the otherlever' by means of whichz the' armature maybe moved, a second part by and means connecting said levers so that they may be shifted together axially with respect to the said pivot tobringthe first named lever into the path of. the second named part, whereby the armature may he means of which the armature may bemoved,

tive swinging movement, means for applying force to one of said levers 1n. .a d rection such asto swing them toward eacliother and means of whichathe armature may be moved,

elastic means, an armature driving abutment in the path of the other lever, a second armature driving abutment, and a lug on the first named lever adapted to engage the second armature driving abutment when said levers are shifted for the purpose of driving the armature without recourse to said elastic means.

In testimony whereof I have atfixed my 20 signature.

PHELPS BROWN. 

